The goal of this project is to define the properties of muscarinic and nicotinic acetylcholine receptors of chick embryo retina before and after synaptogenesis in the retina. Thus far we have elucidated (1) the specificity and affinities of muscarinic and nicotinic acetylcholine receptors for cholinergic agonists and antagonists, (2) the number of receptors were defined as a function of developmental age of the retina, and (3) the location of nicotinic receptors within the retina was determined.